How much pea gravel do I need?

Multiply the area by the depth in feet, then convert to tons at about 96 pounds per cubic foot. Two inches is right for a decorative bed or path, three for a surface people walk regularly. The exception is a playground, where the CPSC recommends nine to twelve inches of loose fill under equipment depending on fall height — an order of magnitude more material than a path, and the figure most people are surprised by. Pea gravel is rounded, which decides where it belongs. Round stone never locks together, so it rolls under load and migrates toward the edges. That makes it comfortable underfoot on a path and a poor choice for a driveway, where angular crushed stone is what you want. For the same reason, edging is not optional: without restraint an unedged pea gravel path thins in the middle and piles at the sides within a season. Put a woven geotextile underneath on soil, or the stone works down into the sub-grade and you will be topping it up every year.